Chronic treatment with estradiol restores depressive-like behaviors in female Wistar rats treated neonatally with clomipramine

Neonatal administration of clomipramine (CMI) induces diverse behavioral and neurochemical alterations in adult male rats that resemble major depression disorder. However, the possible behavioral alterations in adult female rats subjected to neonatal treatment with clomipramine are unknown. Therefore, the aim of this study was to explore the effect of neonatal treatment with CMI on adult female rats in relation to locomotion and behavioral despair during the estrus cycle. Also evaluated was the effect of chronic treatment with E2 on these female CMI rats. We found no effects on spontaneous locomotor activity due to neonatal treatment with CMI, or after 21 days of E2 administration. In the FST, neonatal treatment with CMI increased immobility and decreased active swimming and climbing behaviors. Influence of the ovarian cycle was detected only in relation to climbing behavior, as the rats in the MD phase displayed less climbing activity. Chronic E2 administration decreased immobility but increased only swimming in CMI rats. These results suggest that neonatal treatment with CMI induces despair-like behavior in female rats, but that chronic E2 administration generates antidepressant-like behavior by decreasing immobility and increasing swimming, perhaps through interaction with the serotonergic system.